Fluid-operated percussive tool.



C. 11n- PECL FLUID OPBRATBD PERGUSSIVE TOOL. l APPLICATION FILED APRA28, 1914..

Patented DBG. 29, 1914.

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CORPRATIGN 0F NE'W JERSEY.

raum-ornamenti rriaenssrvn reen To all whom it may concern: A

Beit known that l, Cain il.. Preis, a citi- Zen of the United States,residing at Waverly, in the county ot Tioga and State of New York, havevinvented a. certain new and useful Improvement in Fluid-OperatedPercussive Tools, of which the following is a specification.

This invention relates to pressure operatu ed percussive tools and moreparticularly to tools of the socalled valveleas type.

The object of this invention is to produce a tool of simple constructionand one-which has at the same time high power and low consumption ofoperating luid.

With this object in view a tool has been devised, a practical embodimentof which isI shown in. the accompanying drawing, in which,

Figures l and 2 show longitudinal sections through the tool cylinderwith the piston in dierent positions.

The invention is shown as applied to a plug drill, which comprises acyllnder l of constant diameter throughout its entire length, in whichslides a piston 2. In the l rearward portion of the piston 2 is a boreor elongated cavity 3-the rearward portion of which is of smallerdiameter and cross sectional area than the forward portion. Projectinginto the bore 3 is a Huid inlet plug 4, which has 'a head 5 fitting intothe` @aller diameter portion ofV the bore 3 and a neck 6 of smallerdiameter and cross sectionaluarea. The plug 4'is tubular in shapeforming a fluid inlet passage 7 whereby a constant pressure ismaintained in the bore 3 during the operation of the tool. The lengthsof the larger diameter portion of the bore 3 and of the'head 5 of inletplug 4 are so calculated that the rear edgeof the head 5 will pass intothe larger portion of the bore 3 near the end of the rearward stroke ofthe piston, thus affording a passage for the actuating iuid'to the rearend of the cylinder. From the larger diameter portion of the bore 3 aport 8 opens to the surface of the piston, and .trom the front end ofthe cylinder a passage ,y 9 extends rearwardly opening into the cylin-5o" der again at a point such that it registers with the port 8 near theforward end of the piston stroke. Exhaust ports 10 and 11 are provided,respectively, for the front. and rear ends ofthe cylinder and arepositioned vcylinder for a short Specication of Lettere Estant.Fammi-,bgd Dea, 29g MMA, Application filed April 2S, 1916i, Serial No.835,897.

to he uncoverednear the end of the stroke in each direction` Theoperation of the tool will be evident from the above description. Fluidwill he4 admitted constantly tothe bore 3 through the passage 7 andexert a constant pressure on the forward end of the bore 3. Fluid willalso be admitted through .the rea/r end of the ,portion of the strokewhen the head 5' of the inledplug i has passed completely into thelarger diameter portion of the bore 3 as shown in Fig. 2. To drive thepiston rearwardlyluid will be ad mitted from the bore EL through theport 8 and 'passage 9 for a small portion of the rearward stroke whilethe ort 8 and passage 9 register as shown in ig. l. The eX- -haust ports10 and 11 alternatively exhaust the fluid from the intermittentlysupplied ends of the cylinder.

lt is to be understood that the present showing and descriptiondiscloses only one specified modification of the invention' and otherforms and modiications are included in the spirit and scope of theinvention as expressed in the claims.

1. In a duid operated percussive tool, a cylinder, a piston having anelongated cavity in its rearward portion, an inlet plug, projecting intosaid cavity, having a passage for conveying fluid to exert a constantpressure on the forward end of passages arranged to alternately admitfluid from said cavity to the ends of said cylinder and exhaust ittherefrom.

l2. In a fluid operated percussive tool, a cylinder of constantdiameter, a piston having a bore in its rearward end, the rear ward endof said bore.being of smaller diameter, a fluid inlet tube projectinginto 'said bore said tube havin a head said cavity, and

fitting the smaller portion of the piston bore, i

yportion adapted to register with said piston port near the forward endof the piston stroke, and exhaust ports near the front and rear ends ofthe cylinder.

3. In a fluid operated percussive tool, a

cylinder, a piston having an internal bore 1n lts rearward portion, saidbore being smaller in cross sectional area at itsA rearward end, aninlet plug fitting into said bore and having a passage therethrough forcon veying Huid constantly thereto, said plug also having a head fittingsaid smallerpor with said piston port near the forward end of the pistonstroke, and exhaust ports uncovered by the piston near the end of eachstroke.

In testimony whereof, have hereunto set my hand. y

GAID H. PECK.

Witnesses WALTER S. PECK, WINLFRED S. JOHNSON.

